To the Editor.—In a recent report Hanai et al1 presented the ultrastructural pattern of cultured skin fibroblasts from two patients with I-cell disease and from one patient's parent.
We had an opportunity2 to investigate by electron microscopy, with the technical assistance of Dr. Baroni of "Centro di Miscroscopia Elettronica" of the University of Padova, cultured cells from two patients with Hurler's disease (Fig 1), two patients with Pompe's disease (Fig 2), and two patients with cystic fibrosis of the pancreas (and one parent) (Fig 3). Cultures were grown in T-flasks by a technique described elsewhere.3
In all the cultures we observed the same ultrastructural pattern as described by Hanai et al: that is, single membrane-bound cytoplasmic bodies containing multivesicular membranous figures and variable amounts of dense granular material (Fig 1 to 4). Cultured fibroblasts from two control subjects differed only in the number of cells